A simple JS test to show the difference between $nearSphere and $near

nearsphere_near_difference.js

(function() {
    "use strict";

    let coll = db.geomap_tests;
    coll.drop();

    coll.insert({ _id: "Westfield London", location: [ -0.22157, 51.507176 ] });
    coll.insert({ _id: "Green Lanes Shopping Centre", location: [ -0.098092, 51.576198 ] });

    print("INDEX: 2dsphere QUERY: GeoJSON");
    coll.createIndex({"location": "2dsphere"});

    let result = coll.find({"location":{"$nearSphere":{"$geometry":{"type":"Point", "coordinates":[ -0.127748, 51.507333 ] }}}}, {_id:1});
    printjson(result.toArray());

    result = coll.find({"location":{"$near":{"$geometry":{"type":"Point", "coordinates":[ -0.127748, 51.507333 ]}}}}, {_id:1});
    printjson(result.toArray());

    /*
        print("INDEX: 2dsphere QUERY: legacy");
        Querying using legacy coordinates in 2dsphere index is not allowed.
    */

    coll.dropIndexes();

    coll.createIndex({"location": "2d"});

    print("INDEX: 2d QUERY: legacy");

    result = coll.find({"location":{"$nearSphere":[ -0.127748, 51.507333 ]}}, {_id:1});
    printjson(result.toArray());

    result = coll.find({"location":{"$near":[ -0.127748, 51.507333 ]}}, {_id:1});
    printjson(result.toArray());


    /*
        print("INDEX: 2d QUERY: GeoJSON");
        Querying using GeoJSON in 2d index is not allowed.
    */

    print("");

}());